Once Upon a Time in Shaolin is the seventh studio album by American hip hop group Wu-Tang Clan. It was limited to a single copy sold in 2015, and is the most expensive work of music ever sold. The album was recorded in secret over six years. A single two-CD copy was pressed in 2014 and stored in a secured vault at the Royal Mansour Hotel in Marrakech, Morocco, then auctioned through auction house Paddle8 in 2015. A legal agreement with the purchaser stipulated that the album cannot be commercially exploited until 2103, although it can be played during listening parties.